Observations were made on one eye from a Longman’s beaked whale Indopacetus pacificus, which was probably one of the least known extant cetaceans. The whale died shortly after swimming aground on the coast in the Nis...Observations were made on one eye from a Longman’s beaked whale Indopacetus pacificus, which was probably one of the least known extant cetaceans. The whale died shortly after swimming aground on the coast in the Nishikata Beach, Sendai-shi, Kagoshima-ken Prefecture, Japan, on July 26, 2002. It was a mature female with body length 6.45 m. This paper documented the basic structural characteristics of her visual organ of the whale in order to better understand this animal.展开更多
Past studies have indicated that there are two different stocks (J and O stocks) in the North Pacific common minke whale Balaenoptera acutorostrata population. These two stocks differ from each other in certain charac...Past studies have indicated that there are two different stocks (J and O stocks) in the North Pacific common minke whale Balaenoptera acutorostrata population. These two stocks differ from each other in certain characteristics, such as body size, conception dates, and genetics. However, till date, few studies have investigated differences in the external body appearance between the two stocks. Therefore, in the present study, we focused on the unique white patch on the flipper of this whale species to elucidate inter-stock differences. We used the animals collected from JARPNII research during 2012 and 2013;stock information was determined by microsatellite DNA analysis (n = 220). We focused on the morphological differences in the size and pattern of the white patch on the flipper of each whale. The length of the white patch along the anterior (ventral) margin of the flipper tends to be proportionally larger in O stock. The pattern of the boundary area of the white patch named as the “Grayish Accessary Layer (GAL)” was remarkably different between stocks. Within animals with “no GAL” type, 94% were J stock. Conversely, of animals with GAL expanding over the half the flipper width, 96% were O stock. We concluded from our study that there were clear morphological differences in the flipper color pattern between J and O stocks, which enable to apply widely to other individuals.展开更多
基金the National Science Museum,Tokyo 169-0073,JapanNNSF of China (No.40376042)Natural Science Foundation of Shandong Province (No.Y2007D75)
文摘Observations were made on one eye from a Longman’s beaked whale Indopacetus pacificus, which was probably one of the least known extant cetaceans. The whale died shortly after swimming aground on the coast in the Nishikata Beach, Sendai-shi, Kagoshima-ken Prefecture, Japan, on July 26, 2002. It was a mature female with body length 6.45 m. This paper documented the basic structural characteristics of her visual organ of the whale in order to better understand this animal.
文摘Past studies have indicated that there are two different stocks (J and O stocks) in the North Pacific common minke whale Balaenoptera acutorostrata population. These two stocks differ from each other in certain characteristics, such as body size, conception dates, and genetics. However, till date, few studies have investigated differences in the external body appearance between the two stocks. Therefore, in the present study, we focused on the unique white patch on the flipper of this whale species to elucidate inter-stock differences. We used the animals collected from JARPNII research during 2012 and 2013;stock information was determined by microsatellite DNA analysis (n = 220). We focused on the morphological differences in the size and pattern of the white patch on the flipper of each whale. The length of the white patch along the anterior (ventral) margin of the flipper tends to be proportionally larger in O stock. The pattern of the boundary area of the white patch named as the “Grayish Accessary Layer (GAL)” was remarkably different between stocks. Within animals with “no GAL” type, 94% were J stock. Conversely, of animals with GAL expanding over the half the flipper width, 96% were O stock. We concluded from our study that there were clear morphological differences in the flipper color pattern between J and O stocks, which enable to apply widely to other individuals.
